Endurance Training and its Effect upon the Activity of the GH-IGFs System in the Elderly - Deuschle, M; Blum, W F; Frystyk, J; Ørskov, H; Schweiger, U; Weber, B; Körner, A; Gotthardt, U; Schmider, J; Standhardt, H; Heuser, I (International Journal of Sports Medicine, 1998)